When a vehicle acquires information from a followed, leading vehicle through inter-vehicle communication, this vehicle determines its trajectory, based on this information, thereby performing following drive. More specifically, the vehicle determines a trajectory of the followed, leading vehicle, based on a speed and steering angle of the followed, leading vehicle which have been acquired from the followed, leading vehicle through the inter-vehicle communication. Based on this trajectory, then, the vehicle determines virtual road dimensions in front of the vehicle itself (for example, see PTL 1).